Above & Below the Poverty Line

Why we love it

This map reveals the sobering fact, in nearly every part of American cities, there are people living in poverty. We can see the ratio of households living above and below the poverty line. We also get a clear visualisation of neighbourhoods struggling with poverty and the issues often tied to it. We love this map lets you click on each neighbourhood for more details.

Why it works

A map of ratios can be powerful. In the US overall, there are 6.2 households living above the poverty line for every household living below. This map uses green to indicate areas with a higher than normal ratio of households living above, compared to below, poverty. Orange areas show a higher than normal ratio of households living below the poverty line.

Important steps

Shade for representation

In ArcMap, add the Census ACS data at the tract level for the US. Shade the map by the count of households living above poverty level, divided by the count living below.

Set a standard

For the symbology, centre the map around the average for the US (6.2) and use one standard deviation around that mean to set the break points for the orange and green colours. Use two standard deviations around the mean to set the darker orange and green colours.

Save and present

Serve as a tiled map cache.

Requirements

Data and software

The Census Bureau provides an explicit count of households above and below the poverty line in its ACS offerings. Any two counts can be used in a similar map of ratios. Software used: ArcGIS Desktop, ArcGIS Online.

Analysis

The ratio of one group to another helps tell a story about the national average compared to local conditions. It is equally valid to have the map centre upon a state average, a historical average, or other value.

Time

It will take one hour to create the map and two hours to publish it as a cached tile map service.

Tips and tricks

Complement with the colour wheel

Use complementary colours for the diverging colour ramp, centred around a neutral colour that represents values close to the national average.